Early pregnancy maternal endocrine insulin-like growth factor I programs the placenta for increased functional capacity throughout gestation
Date
2007
Authors
Sferruzzi-Perri, A.
Owens, J.
Standen, P.
Taylor, R.
Robinson, J.
Roberts, C.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Endocrinology, 2007; 148(9):4362-4370
Statement of Responsibility
Amanda N. Sferruzzi-Perri, Julie A. Owens, Prue Standen, Robyn L. Taylor, Jeffrey S. Robinson and Claire T. Roberts
Conference Name
Abstract
In early pregnancy, the concentrations of IGFs increase in maternal blood. Treatment of pregnant guinea pigs with IGFs in early to midpregnancy enhances placental glucose transport and fetal growth and viability near term. In the current study, we determined whether exogenous IGFs altered placental gene expression, transport, and nutrient partitioning during treatment, which may then persist. Guinea pigs were infused with IGF-I, IGF-II (both 1 mg/kg x d) or vehicle sc from d 20-35 of pregnancy and killed on d 35 (term is 70 d) after administration of [(3)H]methyl-D-glucose (MG) and [(14)C]amino-isobutyric acid (AIB). IGF-I increased placental and fetal weights (+15 and +17%, respectively) and MG and AIB uptake by the placenta (+42 and +68%, respectively) and fetus (+59 and +90%, respectively). IGF-I increased placental mRNA expression of the amino acid transporter gene Slc38a2 (+780%) and reduced that of Igf2 (-51%), without altering the glucose transporter Slc2a1 or Vegf and Igf1 genes. There were modest effects of IGF-I treatment on MG and AIB uptake by individual maternal tissues and no effect on plasma glucose, total amino acids, free fatty acids, triglycerides, and cholesterol concentrations. IGF-II treatment of the mother did not alter any maternal, fetal or placental parameter. In conclusion, exogenous IGF-I, but not IGF-II, in early pregnancy increases placental transport of MG and AIB, enhancing midgestational fetal nutrient uptake and growth. This suggests that early pregnancy rises in maternal circulating IGF-I play a major role in regulating placental growth and functional development and thus fetal growth throughout gestation.
School/Discipline
Dissertation Note
Provenance
Description
Copyright © 2007 by The Endocrine Society